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Dentinogenesis Imperfecta Associated with
Osteogenesis Imperfecta: Report of Two Cases |
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Chia-Ling Tsai, BDS, MS
Yng-Tzer Lin, BDS, MS
Yai-Tin Lin, BDS
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Osteogenesis imperfecta (OI) is a heritable systemic disorder
of the connective tissue. Dentinogenesis imperfecta (DI),
which is sometimes an accompanying symptom of OI, belongs
to a group of genetically conditioned dentin dysplasias and
is characterized clinically by an opalescent amber appearance
of the dentin. Although the teeth of DI cases wear more easily
and excessively compared to normal teeth, they do not appear
to be more susceptible to dental caries than normal teeth.
Two cases of DI associated with OI are presented in this paper,
with 1 case suffering from nursing bottle caries. The purposes
of this paper are to present the dental and skeletal characteristics
of moderately and mildly involved DI associated with OI, and
to discuss the possible methods of dental treatment. Patients
with OI and opalescent teeth should be evaluated as soon as
the deciduous teeth erupt; immediate dental involvement and
oral hygiene instruction can be of help in reducing the necessity
of extensive dental care. (Chang Gung Med J 2003;26:138-43)
Key words:
dentinogenesis imperfecta, osteogenesis imperfecta, nursing
bottle caries.
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Osteogenesis imperfecta (OI) is a heterogeneous group of
genetic disorders that affect connective tissue integrity. Most
forms of OI are the result of mutations in the genes (COL1A1
and COL1A2) that encode the pro alpha 1 and pro alpha 2 polypeptide
chains of type I collagen.(1) Tissues in which the principal
matrix protein is type I collagen (mainly bone, dentin, sclerae,
and ligaments) can be affected. The resultant abnormalities
include blue sclera, rigidity of the osseous tissue, hearing
loss, dentinogenesis imperfecta (DI), growth deficiency, laxity
of the joints, and any combination of these characteristics.(2)
The incidence of OI in infancy is about 1 per 20,000-30,000
in an Australian study.(3)
There are extreme phenotypic variations within the OI population.
Four types of OI including mild, perinatal lethal, progressive
deforming, and moderately severe were classified according to
clinical, genetic, and radiographic criteria.(4) Each of the
4 types of OI is further subdivided on the basis of the absence
or presence of DI.(5) However, many OI patients still cannot
be easily assigned to any 1 of the 4 classes because of the
broad spectrum and complexity of molecular abnormalities resulting
in OI.(1)
Molecular genetic studies of OI have identified more than 150
mutations of the COL1A1 (17q21.3-q22) and COL1A2 (7q22.1) genes.
Various systemic treatments for OI (gene therapy or cell therapy)
have been attempted, but these interventions were either inconclusive
or are still experimental.(6)
Dentinogenesis imperfecta (DI) is characterized clinically by
opalescent and translucent dentin due to a mesenchymal defect.
The primary teeth are more severely affected than is the permanent
dentition. The color of the teeth varies from opalescent gray
or brown to yellow, and both upper and lower dentitions are
involved.(7) Radiographically, the crowns of the teeth are bulbous
with marked cervical constrictions, and pulp chambers become
obliterated over a period of time.(8,9) The thickness and radiodensity
of the enamel are normal. Significant attrition can be seen
over a short period of time.(10) The reported incidence in the
US is 1 in 8000 births.(11)
There are 3 types of dentinogenesis imperfecta. Type I is associated
with osteogenesis imperfecta. Type II is the so-called classical
heredity opalescent dentin. Type III is the Brandywine form,
named for the city of Brandywine, MD, where there was a large
population of patients with this disorder. Type III tends to
be less severe than type II.
Dentinogenesis imperfecta has an autosomal dominant pattern
of inheritance. Ball et al. found that the type II locus is
located on 4q13.(12) Types II and III are different expressions
of the same gene.(13) The genes for various forms of OI have
been localized to 17q21.31-q22.05 and 7q21.3-9 22.1, and DI
type I may be associated with these genes.
Some patients with OI display no abnormalities in the dentition,
whereas others manifest significant dentinal involvement. Other
oral manifestations associated with OI include midfacial hypoplasia,
a shortened maxilla with normal mandibular length, class III
malocclusion, and posterior crossbite.(14,15) There are no valid
statistics about DI-associated OI in Taiwan.
The purposes of this article are to present the dental and craniofacial
characteristics of these 2 cases of moderately and mildly involved
OI associated with DI and to discuss the dental management.
CASE REPORTS
Case 1
A 5-year-old Taiwanese girl was referred by her pediatrician
to the pediatric dental clinic at Chang Gung Memorial Hospital,
Kaohsiung; she had complained of a toothache for several days.
She presented facial symmetry with a concave profile and a
class III skeletal pattern.
Her medical history revealed that she had had enlarged posterior
fontanelles, a dilated ventricle, and a fracture of the right
femoral shaft at birth. A diagnosis of OI was made. Although
the child was mentally normal, her physical development was
abnormal. Physical examinations showed that she had limited
motility, bowing of the long bones, shortness of the neck,
kyphoscoliosis, and protuberance of the sternum.
An intraoral examination revealed multiple dental decay and
attrition of the primary teeth. The rampant caries found in
the deciduous teeth was possibly a result of a nighttime nursing
bottle habit. Her remaining intact teeth showed an opalescent
translucent hue.
A panoramic radiograph showed that the intact teeth had bulbous
crowns and small pulp chambers lacking pulp horns when compared
to normal teeth. Those teeth with severe destruction presented
a "shell" appearance of enamel and dentin surrounding
a large pulp chamber and root canals. Three permanent premolars
(15, 35, and 44) were congenitally missing (Fig. 1). A cephalometric
radiograph revealed a shortened maxilla and midfacial hypoplasia.
The patient was diagnosed as OI type IV associated with DI.
For dental treatment, we had to put her under general anesthesia
because of her uncooperative behavior. The dental treatment
procedures included: (a) stainless steel crown on 85; (b)
composite resin restoration on the occlusal surface of 36;
(c) extraction of severely destructed 55, 54, 53, 52, 51,
61, 62, 63, 64, 65, 74, 75, and 84; and (d) 1.23% acidulated
phosphate fluoride application.
At the subsequent 1-year oral examination, the patient showed
a typical Class III malocclusion. The upper central incisors
had erupted and showed an opalescent brown tooth color (Fig.
2).
Case 2
This 7.5-year-old Taiwanese girl was brought by her father
to the pediatric dental clinic complaining of the ugly appearance
of her teeth. She also had a fractured right leg which was
fixed in a plaster cast. Her medical history revealed that
she had had a left clavicle fracture and bruising over the
elbow at birth. She had experienced sustained frequent tibia
fibular fractures since age of 6.
An extraoral examination revealed a symmetrical and straight
profile with a Class I skeletal pattern. Blue sclera was also
noted. An intraoral examination revealed a brown to gray opalescent
tooth color in both the deciduous and permanent dentitions;
we learned that her father and the father's uncle had been
similarly affected. The crowns of the primary teeth were short
and abraded. The incisors were edge to edge and the bilateral
buccal segments were in a crossbite (Fig. 3).
A panoramic radiograph showed that the pulp chamber and root
canals of the deciduous teeth had been partially or completely
obliterated. The permanent teeth lacked pulp horns. The junctions
of the crowns and roots were more constricted than those of
normal teeth (Fig. 4).
Dentinogenesis imperfecta involving both the deciduous and
permanent dentition was diagnosed in this case. She was referred
to the pediatric heredity and endocrine department for a general
evaluation, and a diagnosis of type I osteogenesis imperfecta
(Sillence classification) was confirmed.(4)
Due to only slightly abraded teeth seen in case 2, the dental
treatment plan was to observe her at 6-month intervals. Placement
of artificial crowns will be considered if these teeth are
seen to be rapidly breaking down or fracturing.
DISCUSSION
The aims of dental treatment for children with DI associated
with OI are to ensure favorable conditions for eruption of
the permanent teeth and normal growth of the facial bones
and temporomandibular joints.(16) The oral problems in the
first case included rampant caries with multiple residual
roots, collapse of occlusal height, and hypodontia. A "shell"
appearance of the deciduous teeth (74,75,84) was also found.
Levin (1981) described how the pulp chambers and root canals
in DI may be patent on eruption, and even be larger than those
of normal teeth.(17) Severe dental caries does not seem to
be a major problem in patients with DI and OI. However, caries
appears to inhibit the obliteration process of the pulp chamber,
which results in a wider tooth canal space than with a typical
obliterated canal space in DI. Children diagnosed as having
OI should be seen by a dentist as soon as possible after the
eruption of the deciduous anterior teeth in order to determine
whether there is DI involvement. Dental care for DI includes
caries prevention, attrition observation, and monitoring of
skeletal development. If the deciduous teeth begin to wear,
placement of artificial crowns is recommended before excessive
loss of tooth structure occurs.(17)
In case 1, almost all of the primary teeth were severely decayed
and were removed under general anesthesia. Such rampant caries
was mostly due to an inappropriate nursing bottle habit. An
overlay denture was indicated for rehabilitating the oral
function and occlusion in case 1. However, it was not put
in place because of her uncooperative behavior.
In case 2, the exposed dentin of 52, 53, 62, and 63 was seen
to wearing toward the gingival line, and the primary molars
exhibited excessive attrition with enamel fracture. However,
we did not plan on crowning these primary molars to rehabilitate
the occlusal height, because the caries rate was not high
compared to case 1, and the permanent first molars were intact.
Schwartz and Tsipouras concluded(15) that dental attrition
in DI was less severe in the permanent than in the primary
dentition. Unusual wear does not occur as frequently and to
such a great extent in permanent as in deciduous teeth. Further
esthetic considerations for improving tooth color may be full-jacket
crowns or porcelain veneer crowns on the anterior teeth.(5)
Although bonding of the resin to the defective teeth structure
is theoretically compromised, it is clinically successful
in most patients.(5)
Jensen et al. found that the posture, weight, and size of
the head were abnormal in the OI population, which might contribute
to the development of malocclusion. The more-severe abnormalities
of craniofacial features were associated with the more-severe
types of OI in adult patients.(18) O'Connell et al. reported
that class III dental malocclusion occurred in 70% to 80%
of types III and IV of the OI population, with a high incidence
of anterior and posterior crossbites and open bites.(10) This
was true for case 1 who had a class III skeletal pattern and
a retrusive tendency in the maxilla. Orthodontic and surgical
procedures for correcting the malocclusion are very difficult
because of the easy fracturing tendency in OI patients. Maintenance
of the deciduous teeth is therefore particularly important
to insure normal alignment of the permanent teeth and to reduce
the necessity of extensive orthodontic care. Case 2 had a
class I skeletal pattern, but the mesiodistal dimension of
the primary molars had decreased due to excessive attrition.
Potential crowding of the buccal segments was predicted due
to the decreased arch length. Orthodontic treatment in patients
who suffer from DI associated with OI has not been reported
until now. However, orthodontic treatment has been successfully
performed in patients with different degrees of DI.(19,20)
In conclusion, OI consists of heritable systemic disorders
of the connective tissue. DI is a possible accompanying symptom
of OI and belongs to the group of genetically conditioned
dentin dysplasias. Patients with OI and opalescent teeth should
be evaluated as soon as the deciduous teeth erupt, so that
an attempt can be made to prevent loss of tooth structure.
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REFERENCES
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Bull Tokyo Dent Coll 1996;7:31-49.
15. Schwartz S, Tsipouras P. Oral findings in osteogenesis
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16. Ranta H., Lukinmaa PL, Waltimo J. Heritable Dentin
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17. Levin LS. The dentition in the osteogenesis imperfecta
syndromes. Clin Orthop Related Res 1981;159:64-74.
18. Michael DC. Dentinogenesis imperfecta: a case report.
Am J Orthod Dentofacial Orthop 1998;113:367-71.
19. Battagel JM. Dentinogenesis imperfecta: an interdisciplinary
approach. Br Dent J 1988;165:329-31.
20. Jensen BL, Lund AM. Osteogenesis imperfecta: clinical,
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I, III, and IV. J. Craniofac Genet Dev Biol 1997;17:121-32.
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From the Department of Dentistry, Chang Gung Memorial
Hospital, Kaohsiung.
Received: Apr. 25, 2002
Accepted: Jun. 18, 2002
Address for reprints: Dr. Yng-Tzer Lin, Department of Dentistry,
Chang Gung Memorial Hospital. 123, Ta-Pei Rd., Niaosung,
Kaohsiung 833, Taiwan, R.O.C.
Tel.: 886-7-7317123 ext. 8292;
Fax: 886-7-7317123 ext. 8374
E-mail: woopc@pchome.com.tw
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